To achieve therapeutic effect, a drug must be delivered to its target site. It is a challenge to deliver a drug that is susceptible to enzymatic degradation or cannot cross cell membranes to reach an intracellular target.
Conventional delivery methods include use of target-specific vehicles. See Place et al., Molecular Therapy-Nucleic Acids, 1, e15 (2012). Examples of delivery vehicles include liposomes, polymers, and inorganic nanoparticles. See Gonzles-Toro et al., Journal of American Chemical Society, 134, 6964-67 (2012). However, these vehicles are often toxic or inefficient. See Sun et al., Bioconjugate Chemistry, 23, 135-40 (2012); and Akine et al., Molecular Therapy, 17, 872-79 (2009).
There is a need to develop an efficient and safe vehicle for delivering a drug to its target site.